Traffic controlling system for railroads



July23, 1935. vw. w. WENHOLZ 2,009,007

TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Filed April 50, 1951' BY I 4am m'ronuizv all Patented July 23, 1935 esires stares PATENT osrics r I 2,009,907 V TRAFFIC {CGN'IROLLI-NG SYSTEM FOR YRAILROADS 1 Walter w. Wcnholz, Rochester, N. Y., assignor to 1 General Railway Signal Company, Rochester,

Application, April 30,1931, Serial No. 533,921

, 37 Claims. (01. 246-3) invention relates to a system in which a distant track switch and its associated signal.

are controlled over a comparatively few :line

wires, and wherein these same" line wires are 5 used-tor indicating trafiic conditions at said distaut location.

. In accordance withthe is proposed to control a distant track switch over one line circuit, to control the signals associated with said track switchover another line circuit from a local point, and to indicate at said. local point the position of thertrack switch, the indicating condition of the-signals, theoccupancy Of a detector track :circuit associated with said track switch, the fact whether or-not the switch machine for operating such track section is locked against, such operation by local locking means, and the fact whether the switch machine is a transient or intermediate position In accordance with the present invention, certainof these features are carried out by at times ten-i ergizing a linecircuit from one end and at other times energizing said line circuit from the other end, which is accomplished bythe provision-of means for permitting the use of the line to be shiftedfrom acontrollineto an indication line, and vice versa, without the simultaneous application of current toboth ends of'the line'wire. Provision is made-so that the positions of the switch repeating relay, switch control relay and switch lever must coordinate before a signal can be cleared and if cleared the signal will not be put to stop position if, theswitch lever is inadvertently'manipulated. Provision is also made that if ;the switch lever is manipulated, while the switch locked and a, hands off lamp H0, is lightedQthe switch-will not respond to the lever even though the lock circuit has been restored makingit thus necessary to restore the lever and then manipulate it again. Reversibility of switch in mid-stroke is also provided for, that'is, if the switch should jam in an intern;ediatev position, it may be returned to its original position with out completing itsoriginal stroke. r r i Other objects, purposes and characteristic features of theinventionwill in part be more specifi cally pointed out hereinafter and will in part be obvlous from the accompanying drawing. a f In describing the invention in detail, reference will be made to the single drawing, which shows conventionally one circuit arrangement. and associated devices embodying the present invention, and which illustrates both the apparatus in the central ofiice and at a distant wayside location. Referring tolth'efdrawihgthe track rails 3 have present invention, it

been showntdivided by insulating joints 4, into sections to facilitate track circuiting, of which the detector track circuit containing the track relay T and the track battery 5 only have been shown. This detector track circuit is associated with the track switch S which governs the movement of traffic into and out of the main track and side track, respectively, of the passing siding PS. Withthis track switch Sare associated the main entering signal I and the take-siding signal Id, the starting signal 2 and the dwarf starting signal 2 preferably of asigna'lling system of the rabsolute-permissive-block type, and this switch is operated by the switch machine SM, This switch machine SM is preferably controlled by switch machine control relay WZ, whereas the signals. I, I, 2 and Z are preferably controlled by the signal control relay SZ.

At this way station, there is also provided an approach locking relay AL which is energized only in the event it is safe to operate the track switch S, and which may be controlled in a manner as indicated in the prior application of Wenholz and DeLong Ser. 409,010 filed November 22, 1929; a signal indicating'relay M which is energized onlywhen all of the signals associated with the track switch S are at stop; a switch machine'repeater relay WP; and auxiliary relays X and Y which manifest Whether the switch control linewire Ill is energized from the Way station end, or is connected to thOSWit'Ch'mSuchine control relay WZ. Although only one track switch has been shown, the invention may be applied to all of the apparatus of an entire interlocking plant. 7 v v In the central ofiice DO, there is provided a miniature track layout; whichin every respect corresponds to the railway system to. which the present invention has been applied, of which for convenience only the miniature passing siding ps corresponding to'the actual passing siding PS has beenshownj. This miniature passing siding ps has associated therewith a miniature track switch ms which is operable by the miniature track switch operator SO. With this miniature trackl'ayout, there is also associated a switch control lever SWL, a signal control lever SL, a correspondence relay KR,'a repeater correspondence relay KRP, a signal indicating relay SR, andtwo auxiliary relays-NP and RP, which auxiliary relays manifestwhether the correspondence relay KR. or control energy is connected tothe'dispatchers office end of the linewire l0.

Thecentral ofiice equipment also includes an indicating lamp OS, which indicates the occupancy of the detector track circuit containing track relay T; direction arrow lights W and E which respectively indicate that west bound and east bound traflic is permitted to move over the track switch S; a transient light TL, which indicates that the switch machine is out of correspondence with its controlv relay; a hands-off light HO, which when lighted indicates that. the track switch cannot be operated, and an audible signal BL.

Having now referred to each of the elements of the system, it is believed expedient to explain the operation of the system, this in order to more clearly understand the co-ordination between the various devices and the functions which may be carried out thereby.

Operation The apparatus, as illustrated in the drawing, has been shown in its normal condition, that is, with the track switch S assuming the main track'- position, and the four wayside signals associated therewith assuming the stop position Let us first observe what relays are normally energized and trace their closed energizing circuits. Re-

' ferring to the drawing, it will be noted that the relay NP is energized through the following circuit:beginning at the terminal winding of the relay NP, wire. l2, back contact |3 of the relay RP, resistance unit M, to the common return wire C connected to the midpoint of the central oifice battery. A second energizing cir cuit may be traced for this relay NP as follows:'- beginning at the same negative terminal, winding of the relay NP, wire l5, switch lever SWL, wire l6, polar contact ll of the relay KR in its right hand position, wire, I8, resistance unit l4, to the common return wireC connected to the midpoint of said battery.

Referring now to the way station location, the signal indicating relay M is energized through the following circuit-beginning at the terminal of the way station battery, contact 2 of the signal I closed only when this signal. assumes the stop position, wire 22, contact 23 closed only when the signal I assumes the stop position, wire 24, contact 25' closed only when the signal 2 assumes the stop position, wire 26, contact 21 of the signal 2 closed only when this signal assumes the stop position, winding of the relay M to the other terminal ofthe way station battery.

The switch repeater relay WP is energized to its right hand normal position through a cir cuit which may be traced as follows: beginning at the terminal of the waystation battery, contact 28 of the switch machine SM assuming the main track locked position, wire 29, winding of the relay WP to the midpoint C of the way station battery. The auxiliary relay Y is energized through the following circuit-beginning at the terminal of the way'station battery, front contact 38 of the switch repeater relay WP, wires 3| and 32, stick contact 33 of the relay Y, wires 34 and 55, winding of the relay Y, wire 35, front contact 31 of the approach locking relay AL, to the other terminal of the way station battery. 7

It will be noted, that the correspondence relay KR is normally energized and has included in series therewith the auxiliary relay X of the wayside location. This energizing circuit for the correspondence relay KR may be traced'as follows:-beginning at the terminal of the way station battery, polar contact 40 of the switch control relay WZ, (this relay WZ preferably being one of the two positioned magnetic stick type, so that its polar contacts remain in the position to which the relay was last energized, this relay WZ now being deenergized, but if. desired this relay may include a neutral armature and associated contacts if desired) wire 4|, polar contact 42 of the switch repeater relay WP, wire 43, neutral contact 44 of the relay WP, wires 45 and 46, stick contact 41 of the auxiliary relay X, wires 48 and 49, winding of the relay X, wires 50 and 5|, front contact 52 of the approach lock relay AL, wire 53, front contact 54 of the track relay T, line wire l0, contact 55 of the switch lever SWL, wire 56, back contact 51 of the relay RP, wire 58, winding of the correspondence relay KR, wire 59, front contact of the relay NP, to the common return wire C connected to the midpoint of the way station battery. With the relay KR energized its repeater relay KRP is of course also energized, .and this circuit includes the front contact 6| of the relay KR and the wire 62.

Let use first assume that the. operator in the central ofiice DO wishes to clear the signal 2 to" permit the passage of a train over the track switch S in an eastwardly direction. This may be accomplished by moving the signal lever SL to the right hand position to complete the following circuit:-' beginning at the terminal of the central office battery, signal lever SL, wires 63 and 64', neutral contact 65 of the relay KR, wire 66, polar contact 61 .of the relay KR, wires 68 and 69,wind-' ing of the signal indicating relay SR, line wire 10, winding of the signal control relay SZ, wire H, to the common return'wire Cconnected to the midpoint of the central oflice battery. The completion of this circuit will energize th relay SZ to the right hand position in which the signal 2 is cleared through the following circuit?- beginning at the terminal of the way station battery, front contact 13 of the relay SZ, wire 14 polar contact 15 ofthe same relay, wire 16, front contacts 12 and 11 of the polar home relay 2H (which home relay is energized by current of normal polarity when two blocks in advance of sig-" nal 2 are unoccupied), switch machine contact 18, wire 19 through the mechanism of signal 2 tothe negative terminal of the way-station battery. The signals I, 2 and 2 are preferably 3-position signals of. which the caution circuits, have for convenience, been omitted, and the takesiding signal is preferably 2-position.

' Clearing of the signal 2 will open the contact 21 associated with saidsignal, thereby deenergiz ing the signal repeating relay M and effecting dropping of its contacts 80 and 8|. Dropping of the contact 80 will deenergize the approach lock relay AL '(the detail of which circuit is shown in the prior application above referred to), and dropping of the contact 8| will complete a circuit including the back contact 52 of the approach lock relay AL, which circuit reverses the potential applied to the correspondence relay KR, which circuit may be traced asfo1lows:beginning at the terminal of the way station battery, contact 82 of the relay WZ, wire 83, contact 84 of the relay WP, series resistance unit 85 (having an ohmic'resistance preferably equal to that of the relay X), wire 86, back contact 8| of the relay M, wire 81, back contact 52 of the relay AL, wire 53, contact 54, line wire I0, lever contact 55, wire 56, back contact 51 of the relay RP, wire 58, winding of. the relay KR, wire 59, front contact 60 of the relay NP, to common return wire C connected to the midpoint of the way station battery. The

c esp nce und r e-c ndit on assumed S assumes the main track position, the signal 2 aocaecv 7 flow of current in the relay KR is renersed there-,- by operating its polar contacts inxits :left hand. position. In this connection, it may he pointed out that the relay KR is preferably of such construction that the neutral contacts will not drop during the reversal. of polarity 50f current applied to the relay.

With the relay KR nowlassu-ming its *left :hand position, the energizing circuit for thesignal con: trol relay SZ is-zbroken .at the contact 61 :of the relay KR, but since an auxiliary .stiok circuit including the relays SR'and SZ in series and also.

including i front stick contact 88 of the relay SR and the wire :59 and H12 was previously-closed, the relays SR and SZ are maintained energized. Also, with the relay KR now a'ssum-ing its left hand position the hands-oi? light H0 is energized through the following circu-it: -beginning at the terminal of the central'ofiice battery polar contact 99 of the relay KR assuming its left hand position, wires 9i and 92, hands-off light HO -to the other terminal of the central oihce' batteryfi Also, the east bound signalling lamp E is energized through the following circuit:-beg-inning at the terminal of the central office battery, polar contact Sil'of the -relayK-R its left hand posit-ion, wires -9i and 93, front contact 94 of the relay KRRwire 95, front-contactilfi of the relay wire '97, front eontactlli} of the relay SR, wire 99, signal levereontact Hill, through the east bound signal lamp E (indicating that a signal has been cleared. for east bound trafiic over the track switch S assuming its main track position as indicated by the miniature track switch ms) to the other terminal-() of the central o-iiio'e battery. The'illumination of the hands-off light HO informs the operator that he must not operate his switch lever SLW, this because the switch should not be attempted to be operated, and could not be operated by reason o;f1the"a pproach look relay AL being down, solong as one of the signals associated with the switch S are :in the clear position, 7 Also, if the switch lever 'SWL actually were moved to the opposite position nothing would occur in response thereto, either immediately or after the signal '2 is again put to stop, this because the relay NP would not be stuck up through its front stick contact 155 and front contact it'of relay R ,P because the relayRP cannot be picked up with-the relayKR assuming its dotted left hand position. Furthermore, if he lever L pe t W il the; .v ase e t'h nsi s t on t e la KB cannot be returned to the normal Iighllhand position u ss t lever S L 'first ret rned to h posii n it s m d when hehands-ofi amp HO fi l t dl his'b'ecaus the ontac s .5575? or as. the a e baare out o Let us now bear in mind that the track switch a s m its a oc ed posi on, the a pr ach oc relay AL nd' h si na indicatin e a M are deenergized. Let us further observe what effect the passage of atrain over the detector track c rcuit containing the track relay '1 will have and let us observe how this deenergiz ation or h track e ay T il ener ze t Q -in l h OS associated with the miniature track layoutlps. Let usiassume that east bound train is about re 'l to accept the clear signal 2, and as it does it treads upon the detector track circuit, thereby ceenergizin th t a relay T and-dro pin its contact 55, thereby breaking the energizing, circuit for the correspondence relay KR. heretofore traced.

the dropping. ofiwhichln turn deenerg-izes the re.- peatersrelay .KBP,.-so that the detector track cirou-it occupancy lamp OS is lighted through the following c-irtcuitz;beginning :at the terminal (+9 -,of the-central ofilce lbattery, polarncontact 9B of the relay KR in its left hand position, wires 91 and 19%, neutral contact diet the'relay KRP assuming its-deenergized position wire till, the OlS-ing lamp 08, to the other ti minal of the central ofiice battery. Obviously, the OS lam-p will heextinguished as soon as the track Belay T picks up, thereby informing the operator atthe central iofiiee that the train has passed oe yond the detector track circuit containing track relay and has entered into the single track section.

ll-twill also :be noted that dropping of the relay will deenergi-ze the east bound signal -lam p E. Aisothat the passage of the train by signal 2 will reen-ergize the relay M and the relay AL, thereby i e-applying current of positive polarity to the rela-y KR, leaving the lamp E extinguished until the train h'asprogressed into thesingle track sec tion to a point where relay 2H is reen-er'gized with normal polarity, under which condition relays M and AL are cl eenergized returning the relay to its dotted positionand causing the lamp to be again illuminated; l

' Should the operator now attempt to operate the switch machine SM, he would of course be unable 'to do so because the signal *2 will have again cleared as soon as the train has travelled beyond the zone which governs the home relay 2H, and with the signal 2 clear resulting in deener-gization of the approach relay .A'L 'will prevent operation of the switch machine SM, all in a manner as indicated inthe prior 'applica.- tion above reierred'to, Also, should the opera ator e th sti c l e SWL to e dotted.

position this would .avail him nothing, because the i e s 1 0 1126 connect d o th po ar contact H of the relay KB so 'thatf noyernent o the ver S L will not e ect p king up of he la R1, .1 1 wi l it ef td n ins o "t e relay 'N P. Also, the contact 55 when moved 'to the dotted position would. not complete a .clr, cuit, because thiscircuit would still be'open at the contact J3 of the relay RP. ,jFllrthelmQlffi, he re a KB ann n r zed rowan the right withthe lever SWL out iof correspondence with Ether-clays RP and NP, It is thus "seen that the operator must first return his signallleve r 5Lto the neutral position before he can either extinguish his hands-oil light H9 or operate the switch machine Slifhand when he does this must remanipulatethe lever ,SW-L.

Let ms, th efore assume that t e perato re tu nstln e s al lever SL to e mic dl t n the eb refl ctin cle nere a on o he a s R and SA and i t c nn c ioni shou d be noted that the circuit ,iust broken was a stick circuit and included the stick con-tact 8-8 of the relay SB. :Deenergizationof the signal control relay @SZ will of cm rse return the signal 12 back to its stop position or'conditionrias :in the'eyent --".W'hen light signals are used).,-ithereby effecting energization of the signal repeater relay M, and after a shor t'interval of time,tl1ison*t'he assumption that'there is no train approaching; the relay AL willagain pick up, andwhenthis occurs the original circuit for the correspondence relay KR including the front contactfil of the ap- "proach locking relay AL wi'll'b'e re-closed, thereby energizing the relay "back to itsright hand position, extinguishing the hands-off light HO and extinguishing the east bound lamp E.

Let us now assume that the operator at the central office DO wishes to operate the track switch S to the take siding position, and in order to do so moves his switch machine control lever SWL to the dotted position. This movement of the lever SWL to the dotted position will break the energizing circuit for the relay KR at the contact 55 of the lever SWL, and in so doing will drop the auxiliary stick relay X, which also was included in series with this relay KR having included in series therewith its stick contact 41, so that the energy is cut off of the way station end of the line wire I at the front contact 41 of the relay X. Also, movement of the switch lever SWL to the dotted position effects closure of the following circuit for the relay RP:-beginning at the terminal winding of the relay RP, wires I03 and I04, switch lever SWL, wire I6, polar contact I! of the relay KR, wire I8, resistance unit I4, to the common return wire C connected to mid-point of the central office battery. The completion of this circuit will pick up the relay RP, which by its lifting of con-, tact I3 will stick up the relay NP (this relay NP being slow dropping as conventionally shown) in series with relay WZ through the following circuitz-beginning at the terminal of the central oflice battery, winding of the relay NP, wire I2, front contact I3 of the relay RP, wire I05, front contact I06 of the relay NP, wire I0 1, contact 55 of the lever SWL assuming its dotted line position, line wire I0, contact 54 of the track relay T, wire 53, front contact 52 of the approach relay AL, wires I and I08, back contact I09 of the relay X, wire H0, front contact III of the relay Y (the relay Y still being energized by its stick circuit including contacts and 33) wire H2, front contact H3 of the relay WP, wire H4, winding of the relay WZ, to the common return wire C connected to the midpoint of the central oince battery.

It is thus noted that the relay NP is included in a stick circuit including its own front contact I06 and including the relay WZ in series. The completion of this circuit will of course operate thepolar contacts of the relay WZ to their left hand position, thereby operating the switch machine SM to its take siding position by a suitable circuit conventionally indicated by thedotted line H5 and front contact I2I of relay T.

Attention is directed to the fact that the relays RP and NP are now both energized, and that under this condition the relay KR has both of its terminals connected to the common return wire C and is deenergized, and that with therelays NP and RP both energized the transient light TL will not be illuminated in spite of the fact that the relay KRP has its back contact I I6 closed and the fact that the contact 90 of the relay KR assumes its right hand position.

As soon as the switch machine SM has, however, been unlocked, the relay WP is deenergized and the back contact H3 of this relay WP assumes its retracted position, thereby opening the stick circuit for the relay NP. This stick circuit is maintained opened for a sufficient period of time to allow the contacts of the relay'NP to drop away, as the relay Y is slightly slower acting than either of the relays NP or RP. With the relay NP now deenergized, the transient light TL is illuminated through the following circuit:-

beginning at the terminal of the central office battery, contact 90 of the relay KR assuming its right hand position, wire II'I, back contact H6 of the relay KRP, wires H8 and H9, transient light TL, wire I20, back contact 60 of the relay NP, to the mid-point'C of the central oiiice battery. The illumination of this transient light TL informs the operator that the distant switch machine control relay WZ has been operated in response to the movement of his lever and that the switch machine SM has been unlocked inresponse thereto as manifested by dropping of the relay WP, but that the switch machine has not yet responded completely to the new position of the relay WZ, thus indicating that the switch machine is in a transient condition.

The switch machine is now presumed to be operating toward its take-siding position and the initiation of such operation of course effected deenergization of theswitch machine repeater relay WP as soon as theswitch machine was unlocked mechanically, and with the auxiliary relay X now deenergized the opening of the contact 30 of the relay WP effects deenergization of the auxiliary relay 'Y, so that both the relays X and Y are deenergized.

Let us assume for the purpose of considering the operation of the switch machine when stalled in mid-stroke at this time. With the relays X and Y both deenergized and the relays WP also deenergized it will be noted that the control re lay W2 is again connected to the line wire I 0 through the following partial circuit:beginning at the line wire I0, front contact 54 of track relay T,-wire 53, front contact 52 of approach relay AL, wires 5I and I08, back contact I09 of relay X, wire I I0, back contact III of relay Y, wire I22, back contact II3 of relay WP, wire H4 to the relay WZ, It is thus apparent that the operator is free to operate the switch machine SM if it should be stalled in mid-stroke, this by reason of the partial circuit just traced including the wire I22 and the back contacts III and I I3 of the relays Y and WP, it of course is understood that the operator is free to apply energy of either polarity to the line wire I0 from the central oilice DQif he so desires, this because the polar contacts of the relay KR now assume their right hand position.

Let us now assume that the switch machine has completedits operating stroke to the take siding position, and in so doing has energized the switch repeater relay. WP to its left hand energized position, thus bringing it into correspondence with the polar position of the relay WZ With the relays WZ and WP assuming corresponding polar positions and with the relays X and Y still deenergized, as heretofore explained, the following circuit for the correspondence relay KR is completed:beginning at the negative terminal of the way station battery, contact 82 of the relay WZ assuming the left hand position, wire I23, polar contact 42 of the relay WP assuming the left hand position, wire 43, front contact 44 of the relay WP, wires 45 and I24, back contact I25 of the relay Y, wires I26 and 49, winding of the relay X, wires and 5|, front contact 52 of the relayAL, wire 53, front contact 54 of the relay T, wire I0, contact 55 of the lever SWL assuming its dotted position, wire I01, back contact I06 of the relay NP, wire 59, winding of relay KR, wire 58, front contact I21 of the relay RP, to the common return wire C connected to the midpoint of the way station battery. It is to be noted that'this circuit for the relay KR has been pole changed on the energy end, and the ter-.

or course operatethis relay to its right handrposie tion, and will effect picking of the series relay X; With the relay X now picked up andw'ith the: relays AL and'WP in the'ir energized position the relay will again be picked up througl'r'the iollo'wiii'g' pick-up circuit:'be'ginning. at the terminal of the way station battery} front con v tact 3'6 o'fthe relay WP, wires 3! and its; front contact [31' of the any X, wires Hi2 and 375, win-dihg of the relay Y, Wire fronticontact" 31 of the relay AL,- to the other terminal (-I. of the way stationbattery- With the relay Y once picked orbit is stuck up through its stick contact 33,- a d the circuit just traced for the relay KR is nowpmsed tlrr oug-h-th'e' frontcontact 4"! of the may X'iiis'te'ad of the back Contact $25" of the rla yY, r the relay' KR" is picked up through the coil cuit last traced forthis relay KR, and before the repeater relay KRP: had suflic'i'ent-ti-me to: pickup; a circuit is momentarily closed for the miniature track switch 'operator SO- which may be traced as renews i b'ginzhing at the terminal oflthe centimetresbat'tery, contact git-of the relay KR. assuming its right hand positionywire HT; back contact NE of therelay KRP, wires H8 and 134, from;- contact I35 of the' relay KR, wire I36, con tact (3? of the sn'zitchmachine lever SWL assuming the dotted position,-wire $38, the reverse-operstingcoil of the miniature-track switch operator S; to the common were (3 connected to the midpoint'of the central oifi'c'e battery. It is of course understood'thatt he transient light 'I'Iu is extinguished upon picking up of the repeater relay KRP occursimmediately afterthe miniai ture track switch operator S0 is operated to its new position Summary" 7 Referringto the drawin'gfit is readily apparent that-theline' circuit i i! for operatin'gthe switch -control relay WZv is normally energized fromthe waystation' end; and this is true irrespective of whether the relays andM are bothenergized or are both deeiiergized, this line circuit IO being energized by one polarity with the relays AL and M eneigizd and being energized with current of the other'polarity with therelays and: M deen ergized. Also, operation of the switch control lever SWL will effect opening of said line circuit at the contact 55, this irrespective of the rapidity which the lever SWL is operated; this by reasonof the fact that the relays RP and NP are slow picking up; and that during this deenergization or the l'i'ne circuit It the relay is deene'rgized, thereby'remo-ving the source of currentfron'i the" way station end of this line circuit to. Also, since relay X drops quickly'one' of the rciays RP oiNP will be stuck up" through the line circuit H1 in series with the relay WZ. Furtheiz'n'ore, it is readily seen that the; relay WZ cannot be connected to the line wire Hi unless the relays WP and Y are either botnenergized or are both deenergized' while the relay X is deenergized; readily seen from the contacts" HI and H41 of relaysY and It is also seen that the relays Y and WP will remain in their normal energized condition unless'either the; approach relay AL- is deenergizedand-opens its contact 31, or the'switch machine relay WP is deen-ergized as itwmild in response; to initiation or operation of the switch Ina-chine SM, so; that the relay WZ can biecontio lled from the line Wire m with the relay down so long as, the switch .niachine S-M has not already been initiated or the approach relay deenergize'd by reason of a hazardous trailic approaching" condition.

Referring now more particularly to the apparatu's in the central ofiice DO it will be noted that the: control relay WZ can. only be energized in; series withone of the relays RP or'NP, and that this can occur only when the otherrelaytNP'orRP is also energized, from which it appearsithat one of the relays RP or NP are included. in'ai'stick' circuit, and that .if the line circuit is open during this conditionthat" the particular one of. these frelays RP or NP which is included such" stick circuit will assume its deenergi'zed position; and; that this occurs as soon as: the relay WP is" deen'ergized as it will in response to operation of the switch machine in response tofxa change in the position of the con-L tro l relay WZ due to'the circuit under consider ation. A-1 'sot,-it will/be noted that, they relay "KR can only assume an energized position when-the relays; R-P NP assume non-corresponding positions; that the: relays R5? or NP cannot be picked up: unless'the relay KRiassumes its right hand normali-position,.and that the relay KR will be energ'mect to its left hand dotted positionwhen the relays and M assume their deenergized position? manifestinga' proceed indication by one of the waiyside signals t, i 2; and 1", from which it is. apparent that movement or the lever SWL will: not; permit operation. of the switch: machine SM so long as one ofiithese signals I; N, 2 and 2 this condition theihands-ofi' light H0 is illuminated.- in other words; if; the operator should movej'thc lever when the hands off light H0 is illuminated no response of the switch machine will takeplace either immediately or after the cleared signal? hasbeen put to stop as may be done byj operating the signallever SL, and the 'ope'raitor'must re-imanipulate his. lever- SWL to effectoperation'of the switch machine SM. Attentioniis alsotdirected to the fact that the signal relay SZ can only bevenergized with the relay KR rener'g'izedztowardthe right; andjthat the relay KR will: be energized toward; its left hand position asrsooni as onje of the signals I; l- 2i and 2 assumes a-aclear ipositionin response to energizationof the signal-relay S'Z, and that movement of-the relay KR: to itsleft hand position will open the original energizing circuitfor therelay SZ at the contact 61 ortherelay KR, but, that this signal circuit including relays SR and SZ will remain intactthroughthe stick contact 90 of therela-y SR. 'Hafvin'g thus, shown and described one rather specific embodiment of the present invention andhaving illiustratedf this embodiment of the in'ventionvihr considerable 7 detail; it is" desired to be understood thatthi-sjhas not been done ior the pu'rposetoffshowing the scope of the invention nor the exact construction preferably'employed in practicing the same but has been resorted to in order to facilitate description of the underlying principles of the invention and one manner in which these principles may be taken advantage of, and it is further desired to be understood that various changes, modifications and additions may be made to the particular embodiment of the invention illustrated to adapt the same to the particular problem encountered in practicing the same, all without departing from the spirit or scope of the invention, except as demanded by the scope of the following claims.

What I claim as new. is:

1. A switch control system comprising, a cen-' tral office, a distant way station, a traffic controlling device at said way station, a circuit connecting said oifice and way station, means for controlling said traffic controlling device over said circuit by current derived from a source at said central ofiice and automatically removed when said trafiic controlling device has responded to such current, a stick means for giving an indication at said ofiice of the condition of said traffic controlling device by being controlled by said current flowing over said circuit from a source at said central office.

2. A switch control systemicomprising, a central ofiice, a distant way station, a trafiic controlling device at said way station, a circuit connecting saidofiice and way station, means for controlling said traflic controlling device over said circuit by current derived from a source at said central ofilce and automatically removed when said traffic controlling device has completely responded torsuch current, a stick device at said Way station for when deenergized permitting control of said traflic controlling device controlled over said line circuit from a current source at said central ofiice, and indicating means at said oflice controlled over said circuit from a source at said way station.

3. In combination, a line circuit connecting a central oilice and a distant way station, a polar stick device at said way station, an electroresponsive indicating device at said central ofllce normally energized from a source of current at said way station, means at said way station for removing said Way station source from said line circuit a short period of time following momentary opening of said line circuit, means at said central office including a lever which upon operation of said lever will momentarily open said line circuit and then energize it from the ofiice end to effect operation of said polar stick device, and means at said way station for preventing energization of said line circuit from said way station end if said stick device is out of correspondence with the device it controls.

fl. In combination, a line circuit connecting a central office and a distant way station, an electroresponsive indicating device at said centraloffice normally energized from a source of current at said way station, means at said way station for removing said way station source from said line circuit a short period of time following momentary opening of said line circuit, and means at said central office including a lever which upon operation of said lever will momentarily open said line circuit and then energize it from the office end. I

5. In combination, a line circuit connecting a central ofiice and a distant way station, a polar stick device at said way station, an electro-responsive indicating device at said central office normally energized from a source of current at said way station, means at said way station for removingsaid way station source from said line circuit a short period of time following momentaryopening of said line circuit, means at said central oince including a lever which upon oper-. ation of said lever will momentarily open said line circuit'and then energize it from the ofiice end, and means effective upon operation of said polar stick device for preventing said line circuit being energized from said way station end until a traflic controlling device controlled by said stick device has responded to the changed condition of said stick device.

6. In combination, a line circuit connecting a central ofiice and a distant way station, a polar stick device at said way station, an electro-responsive indicating device at said central oflice normally energized from a source of current at said way station, means at said way station for removing said way station source from said line circuit a short period of time following momentary opening of said line circuit, means including a lever at said central oflice whereby operation of said lever will momentarily open said line circuit and then energize it from the oflice end, and means including an electro-responsive stick device for preventing said line circuit being re-energized from said way station end until a trafiic controlling device controlled by said stick device has responded to the changed condition of said stick device. v

7. In combination, a line circuit connecting two stations of a railway system, a lever at one ofsaid stations for controlling a trailic controlling device to either of two positions, a polar relay at said one station having its windings directionally connected in said line circuit in accordance with the position of said lever, and means including a source of current at the other station for energizing-said line circuit in accordance with the position of said'trafiic controlling device controlled by saidlever.

8. In a traffic controlling system, the combination with a central ofiice and a distant way station, a line circuit connecting said office and way station, multi-polarity energy applying means and :a polar relay at said office, means for including either said energy applying means or said polar relayin said circuit and for including said polar relay in a particular polar direction in said circuit in accordance with the last polarity of current applied to said line circuit by said energy applying means, and means at said way station controlled by said energy applying means and for applying current from a source at said way station to said polar relay over said line circuit.

9.'In a trafiic controlling system, the combination with a central ofiice and a distant way station, a line circuit connecting said oflice and way station, opposite polarity energy applying means and a two position polar relay at said office, means for including either said energy applying means or said polar relay in said circuit and for including said polar relay in a particular polar direction in said circuit in accordance with the last polarity of current applied to said line circuit by said energy applying means, and means at said way station controlled by said energy applying means and'for applying current from a source at said way station to control said polar relay to one or the other of its polar positions .over said line circuit.'

10. In a traffic controlling system, the combiacne-now nation with a central'ofiice and a distant way station, a line circuit connecting said ofiice and way station, multi-polarity energy applying means and a polar relay at said Ofiioame'ansfor' including either said energy: applying means or said polar relay in said circuit and. for including said polar relay in said circuit in accordance with the last polarity of current applied tosaid line circuit by said energy applying means, and means at said way stationcentrolled over saidline cir cuit by said energy applying means and for applyingcurrent from a source at said way station to said polar relay over said line circuit.

l1. Ina traffic controlling; system,- the conibination with a central OffiC'e anda distant way station, a line circuit connecting said oince and-way station, mul ti-polarity energy" applying means and a polar relay at said oifice, means for includ ing either said energy applying meansor said polar relay in said circuit and for including said polar relay in a particular polar direction in said circuit in accordance with last polarity of current applied to said line'circui-t by said energy applying means, and traffic controlling inean's a't said way station controlied'o'yer said line circuit by said energy applying means and including means for applying current from a source at so d Way station to said line circuit to control said pol'ar relay in accordance with the operated condition of said traffic controlling means.

12. In atrafiic control-ling system, the combination with a central ofiice and a distant way'station', a line circuit connecting said office and'way station, opposite polarity energy applying means and a polar relay at said ofiice, means for including either said energy applying means orsaid polar rela (in said circuit and for including said polar relay in a particular polar direction in said ircuit in accordance With the last polarity of current applied to said line circuit by said energy applying means, and a control relay at said way station'c'ontrolled by said energy applying means and having contacts for controlling said polar relay only in the event suitable trafiic controlling means controlled by said control relay assumes a condition corresponding to the position assumed by'said control relay.

13. In a trafiic controlling system, the combination with a central office'and a distant way station, a line circuit connecting said office and way station, opposite polarity energy applying means and. a polar relay at said office', means for including either said energy applying means or said polar relay in said circuit and for including said polar relay in a particular polar direction in said circuit in accordance with the last polarity'of current applied to said line circuit by'said energy applying means, and a control relay at sai'd way station controlled by said energyappiying means and having contacts forcontrolling said polar relay only in the event suitable traffic controlling means controlled by said control relay and said control relay are in correspondence.

14. In a train" controlling systemgthe comb-i;- nation with a central ollice and a distant way station, a line. circuit connecting said oifi'c'e and way station, opposite polarity energy applying means and a polar relay at said oilice, means for including either said energy applying means or said polar relay in said circuit'and for including said polar relay in a particular polar direction said circuit in accordance with the last polarity of current applied to said line circuit by' said en- 7 ergy applying means, and meansat said way's'tation' for non-simultaneously controlling said polar relayi and receiying'governing current trend said energy applying means and including means for preventing energy from being appliedto said l ine. circuit at said way station when said energy applying means at said ofiice is applying energy to" said line" circuit, r

15'. In combination, way station, a linecircuit connecting said ofii'c'e' and way station, a lever at .saido liice', a polar relay at said oflice include-b le in said circuit in a polar direction only in accordance with the position of said lever, a track switch at said way station, a signal for governing the movement of trains over said track switch, and means at said way station for energizing said line circuit and in tu-rn 'said polar relay by current of a polarity depending on a central others, a distant the position of said switch when said signal is at line circuit and in-turnsaid polar relay by current of a polarity depending on the position of said switch whenanyone of saidsignals is at proceed and energizing said line circuit by current of the reverse polarity for the same posit" n. of said switch if said signals are all at stop? 17. In combination, central ofiice, a distant way station, a line circuit connecting said o ifice and way station, a lever at said office, a polar relay at said ofiice includable in said circuit in a; polar direction only in accordance with the position of said lever, a track'switch at saidway station, an approach locking relay for locking said switch; and-means at'saidway station for energizing said line circuit and in turn said polar relay by current of a polarity depending on the position of said switch when said approach lock ing relay is energizedand energizing saidline circuit by current of the reverse polarity for the same positionof said switch if said'app'roach locking relay is deenergized. a

16. In combinatiom-means for con-trolling a switch machine in" accordance with the polarity of current of a: particular character transmitted wholly'over a single line circuit from a source at aoentral ofiice and for transmitting anindication to said central since by current of the same character over saidline circuit but from a source at said way station and having a polarity corr'e spending to theposition of said switch machine". 19."In combination, a line wire connecting a localoilice and a distant way station of a railway system, a source of energy at each end-of said linecircuit, a control relay at said way-station, an indicating relay at said oflice, a way station series relay included'in series with the way station source when said indicating relay is ener gized, an oflice series relay included in series with said office sourcewhensa-id controlrel'ay is energized, and means for excluding said respective series relays from said respective sources.

20. In combination, aline wire-connecting a l'ocaloffice and a dista-ntwaystation orarauway system, a trafiic' controlling device aftsaid way station, a'sourc'e' of energy at each end of said line circuit, a: control" relay-at saroway-station for controlling said trafiic controlling device, an indicating relay at said oflice, a way station series relay included in series with the way station source when said. indicating relay is energized, an office series relay included in series with said office source when said control relay is energized, and means 'for excluding said respective series relays from said respective sources by momentary opening of said respective energizing circuits.

21. In combination, a line wire connecting a local ofilce and a distant way station of a railway system, a trafiic controlling device at said way station, a source of energy at each end of said line circuit, a control, relay at said way station for controlling said traiiic controlling device, an indicating relay at said oifice, a way station series relay included in series with the way station source when said indicating relay is energized, an. oflice series relay included in series with said ofiice source when said control-relay is energized, a front contact on each of said series relays included in series with their respective windings, whereby momentary opening of the respective energizing circuits will result in excluding the respective series relays.

22. In combination, a line wire connecting a local office and a distant way station of a railway system, a traffic controlling device at said way station, a source of energy at each end of said line circuit, a control relay at said way station for controlling said trafiic controlling device, an indicating relay at'said ofiice, means for energizing said control relay through said line wire from said office source through a front contact and the winding of a series relay at said office, means for energizing saidindicating relay through said line wire from said way station source through a front contact and the winding of a series relay at said way station, whereby momentary opening of either of said energizing circuits results in opening of such circuit at the energy source end thereof. 7

23. Incombination, a line wire connecting a local office and a distant way station of a railway system, a trafiic controlling device at said way station, a source of energy at each end of said line circuit, a polar control relay at said way station for controlling said traffic controlling device, a polar indicating relay at said ofiice, means for energizing said control relay through said line wire from said oflice source through a front contact and the winding of a series relay at said oiiice and a back contact of a series relay at said way station, means for energizing said indicating relay through said line wire from said way station source through a front contact and the winding of a series relay at said way station and a back contact of said series relay at said ofiice, whereby momentary opening of either of said energizing circuits results in disconnecting the source of current and substituting a polar relay therefor.

24. In a traiiic controlling system for railroads, the combination with a local office and a distant point on a railroad, of a line circuit connecting said oifice and distant point, a track switch at said point, a switch machine for operating said track switch, a signal for governing traffic over said track switch, and means including a control lever for controlling said switch machine over said line circuit in accordance with the polarity of current applied to said line circuit at the office end thereof and for indicating at said oflice the correspondence between said lever and switch machine by the application of current to said line wire of one polarity at'said distant point and im dicating at said oiiice a proceed condition of said signal by the application of current of the reverse polarity at said distant point.

25. In combination, a line circuit connecting two stations, a source of energy at both of said stations, means at both of said stations for connecting and disconnecting its source to said line circuit, said means being effective to disconnect its respective source from said line circuit when said line circuit is momentarily deenergized to thereby allow the source at the other station to be connected, and means at both stations controlled by the energized and deenergized condition of said line circuit.

26. In combination; a first station; a second station; a line circuit connecting said first and second stations; a source of energy at both of said stations; control means at both of said stations for at times connecting or disconnecting said sources in series in said line circuit, said control means at said first station normally disconnecting said source from said line circuit, and said control means at said second station normally connecting its source in said line circuit; means associated with each of said control means causing that particular one of said control means having its source connected in series in said line circuit to disconnect its source upon momentary deenergization of said line circuit to allow the other control means to connect its source in said line circuit; means at each station for at times momentarily opening said line circuit; and means at each station at times controlled by a source of energy at the other station over said line circuit.

2'7. In combination, a line circuit connecting two stations of a railway system, a lever at one of said stations for controlling a traffic controlling device at the other of said stations to either of two positions, a polar relay at said one station having its winding reversibly connected in said line circuit in accordance with the position of said lever, and means including a source of current at said other station for energizing said line circuit with one polarity or the other in accordance with the position of said traffic controlling device controlled by said lever. 28. In a system for governing power operated track switches, an outlying track switch, a control lever for governing the operation of said track switch, a miniature track switch associated with said control lever, indicating means effec tively actuated only when said control lever and said track switch are in corresponding positions, and electro-responsive means governed only momentarily in accordance with the position of said lever and only when said indicating means is effectively actuated to thereby actuate said miniature track switch.

29. In a trafiic controlling system for railroads, a central ofilce, a distant way station, a traffic controlling device at said way station, a circuit connecting said oflice and said way station, means for controlling said traffic controlling device over said circuit by current derived from a source at said central office, a stick relay having a stick circuit energized by said current in said circuit, means for opening said circuit when said traflic controlling device responds to said current in said circuit, whereby said stick circuit is deenergized, and an'indicator controlled by said stick relay to indicate the response of said trafiic controlling device.

30. In a traflic controlling system for railroads; a central ofiice; a field station; a line circuit connecting said oflice and said field station; a control lever at said central ofiice having normal and reverse positions; normal and reverse stick relays at said oil-lee; pick up circuits for said normal and reverse stick relays closed when said lever is in corresponding normal or reverse positions; stick circuits for said normal and reverse stick relays, each of which circuits includes a contact of the opposite one of said stick relays, said lever in an opposite position and said line circuit; a polar relay at said field station responsive to the current flow in said line circuit when both of said stick relays are picked up to. thereby control a trailic governing device at such field station; means for momentarily opening said line circuit when the traffic governing device responds to its control by said polar relay, whereby the stick circuit for said normal or reverse relay is open depending upon the position of said control lever; and indication means controlled by said normal and reverse stick relays.

31. In combination, a local ofice and a distant point, a pair of line wires connecting said office and point, a track switch at said distant point, a switch machine for controlling said track switch, manual means at said oflice for controlling said switch machine over said line wires, a polar relay at the office end of said line wires, and means for controlling said polar relay over said line wires to one polar position when said manual means and said switch machine assume corresponding positions and for controlling said polar relay to the other polar position when a signal for governing traflic over said track switch has been cleared.

32. In combination, a local oflice and a distant point, a pair of line wires connecting said office and point, a track switch at said distant point, a switch machine for controlling saidtrack switch, manual means at said oifice for controlling said switch machine over said line wires, a polar relay at the ofifice end of said line wires, and means for controlling said polar relay over said line wires to one polar position when said manual means and said switch machine assume corresponding positions, for controlling said polar relay to the other polar position when a signal for governing tramc over said track switch has been cleared, and deenergizing said polar relay when there is a train moving over said track switch.

33. In a centralized trafilc control system for railroads, a track switch, a switch machine for operating said track switch, a free and non-lockable control lever for governing operation of said 7 switch machine, indication means at times governed in accordance with the position and locked condition of said track switch, and means indieating a lack of correspondence between said control lever and said indication means initiated upon movement of said lever and remaining effective until said track switch starts to operate.

34. In a centralized trafiic control system for railroads, a track switch, a switch machine for operating said track switch, .a control lever for governing operation of said switch machine, indication means being at times governed in accordance with the position of said track switch, means registering a lack of correspondence between said control lever and. said track switch until said track switch starts to operate, and an indicating lamp governed both by said indication means and by said means registering a lack of correspondence between said control lever and said track switch.

35. In a centralized traffic control system for railroads, a trafiic controlling device, a free and non-lockable control lever for manually governing operation of said traflic controlling device, indication means selectively governed to indicate the condition of said trafiic controlling device, means registering the lack of correspondence between said control lever and said traflic controlling device initiated upon movement of said lever and effective until said trafiic controlling device starts to operate, and an indicator governed both by said indication means and by said registering means.

36. In combination; a track switch; a switch machine for operating said track switch; a freely movable control lever for governing operation of said switch machine; indication means only intermittently governed by the position or unlocked condition of said track switch; a relay rendered active whenever said control lever is out of correspondence with the position of said track switch as indicated by said indication means; and means maintaining said relay rendered active, independently of said lever and said indication means, if once rendered active, until said switch machine starts to operate said track switch.

37. In combination, a track switch, a switch machine for operating said track switch, a free and non-lockable control lever for governing the operation of said switch machine, indication means at times jointly controlled in accordance with the position of said track switch and said switch machine, means distinctively controlled when said control lever is out of correspondence with said track switch and said machine as indicated by said indication means, and other means for maintaining the distinctive condition of said means until said track switch starts to .operate.

WALTER W. WEN HOLZ.

DISCLAIM ER 2,009,( )O7.Walter W. Wenholz, Rochester, N. Y. TRAFFIC CONTROLLING SYSTEM FOR RAILROADS. Patent dated July 23, 1935. Disclaimer filed October 10,

1936, by the assignee, General Railway Signal Company. Hereby enters this disclaimer to claims 18, 19, and 20 of said Letters Patent.

[Ofiicial Gazette November 3, 1.936.] 

